Absorption refrigerating machine



June 6, 1961 E. M. STUBBLEFIELD ETAL 2,986,996

ABSORPTION REFRIGERATING MACHINE S SheetS-Sheet 1 Filed June 23, 1958 wSE n Rm w 0 E O\ n! T M vm ulnar. MSW R E vw... m W W T ME v4 D R M wHHHHHII H w June 6, 1961 E. M. STUBBLEFIELD ETAL 2,986,906

ABSORPTION REFRIGERATING MACHINE 3 Sheets-Sheet 2 Filed June 23, 1958 wE m n T E E m N E 8 R V R O mmu v" M A o g WP m.

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June 6, 1961 E. M. STUBBLEFIELD ErAL 2,986,906

ABSORPTION REFRIGERATING MACHINE Filed June 25, 1958 3 Sheets-Sheet 3 p2,986,906 ABSORPTION REFRIGERATING MACHINE Edward M. Stubblefield andler Edberg, La Crosse, Wis., assignors to The Trane Company, La Crosse,Wis., a corporation of Wisconsin Filed June 23, 1958, Ser. No. 743,798 7Claims. (Cl. 62-487) This invention relates to refrigerating and moreparticularly to a self-contained or unitary refrigerating apparatus ofimproved construction.

The principal object of the present invention is to provide a unitaryrefrigerating apparatus in which the generator, condenser, absorber andevaporator are enclosed in a single shell with passageways internal ofthe shell for the flow of refrigerant from the generator to thecondenser and from the evaporator to the absorber.

It is another object of the invention to provide a structure in whichwalls of the generator and condenser serve to separate the high pressuresection from the low pressure section of the shell.

It is another object of the invention to provide a compact andeconomical absorption refrigerating apparatus embodying an eflicientarrangement of the elements of the system which assures efiicientoperation and which reduces the space required for the apparatus in use.

Still another object of the invention is to provide an absorptionrefrigerating machine of the type indicated which is of simplerconstruction requiring fewer parts and less material, and one which ismore economical to manufacture requiring fewer welds and less leaktesting than previously known refrigerating uni-ts of! the samecapacity.

These and other objects will become more apparent from the followingdescription and drawings in which like reference characters denote likeparts in the several views. It is to be expressly understood, however,that the drawings are for the purpose of illustration only and not adefinition of the limits of the invention, reference being had for thispurpose to the appended claims. In the drawings:

FIG. 1 is front elevational view partly diagrammatic of the absorptionmachine of this invention;

FIG. 2 is an end elevational view as seen from the left of FIG. 1;

FIG. 3 is an end elevational view as seen from the right of FIG. 1;

FIG. 4 is a sectional view taken on line 4-4 of FIG. 1; and

FIG. 5 is a partial side view with portions of the casing and interiorstructure broken away to more clearly show the interior construction.

Referring now to the drawings, there are provided feet secured to andsupporting a horizontally extending drum or shell 12. Shell 12 enclosesa longitudinally extending absorber 14 in its lower portion. We preferthat the absorber shall be substantially centered with respect to thevertical longitudinal diametral plane of the shell 12. A longitudinallyextending evaporator 16 is mounted in the shell 12 above the absorber14. We prefer to mount the evaporator 16 offset from the verticallongitudinal diametral plane of the shell 12. Also mounted in the shell12 above the absorber 14 and to one side of the evaporator 16 is agenerator 18. A longitudinally extending condenser 20 is located in theshell at the top. The condenser 20 is approximately centered withrespect to the vertical longitudinal diametral plane of the shell 12 andit is therefore horizontally offset from the generator.

The absorber 14 has a plurality of tube supports 22 States Patent C)which support tubes 24. Tubes 24 communicate with an inlet header 26 andan outlet header 28. Cooling water flows through the absorber 14 viainlet header 26, tubes 24, and outlet header 28.

Spray trees 30 distribute the solution over the tubes 24 whereby heat istransferred from the solution to the cooling water flowing in the tubes24. The solution then flows out of the shell through pipe 32. A strainer33 prevents foreign particles from entering pipe 32.

Various combinations of refrigerant and absorbent may be used in thepresent machine. A solution of lithium bromide and water has been foundto be highly satisfactory for use. Other salt solutions may be used ifdesired. For instance, the solution may be lithium chloride and water orsodium hydroxide and water. When it is necessary to produce lowtemperatures, other absorbent and refrigerant combinations may be used.When lithium chloride and water are used, the system will be under avacuum with the generator and condenser at a higher absolute pressurethan the evaporator and absorber.

A solution recirculating pump 34 has its inlet connected to the pipe 32and pump 34 discharges into pipe 36 which is connected to the spraytrees =30. The solution sprays greatly increase the surface area of thesolution thus increasing the absorption capacity. The movement of thesolution over the tubes increases the heat transfer.

The evaporator 16 has horizontally extending walls which form with theend walls 38' and 40 of the shell an evaporator compartment 42.

Tube supports 44 are secured to the walls of the evaporator compartment42 and support the evaporator tubes 46. Chilled water from arefrigeration load such as air conditioning devices enters theevaporator tubes 46 through header 48 and leaves through header 50.

Refrigerant is sprayed over the tubes 46 from a spray tree 52. Theunevaporated refrigerant leaves the shell through a pipe 54 leading to arefrigerant reservoir 56. A refrigerant pump 58 is connected to drawrefrigerant from the reservoir 56 and to discharge the refrigerant intoa pipe 60 which is in fluid communication with the spray tree 52. Themovement of the sprayed refrigerant over the tubes improves the heattransfer.

The solution in the absorber 14 absorbs water vapor from the refrigerantin the evaporator 16 thus establishing a reduced pressure in theevaporator. At the reduced pressure, the refrigerant boils. The chilledwater flowing in the tubes 46 transfers its heat to the refrigerant andis itself reduced in temperature so that it may be circulated again tothe refrigeration load. The water vapor flows from the evaporator to theabsorber through a passageway 62 between the evaporator 16 and thegenerator 18.

It is apparent that the solution in the absorber 14 is diluted by thevapor from the evaporator and that there must be some means forconcentrating the solution if the process is to be sustained. A pump 64receives dilute solution from the absorber 14 through a pipe 66 anddischarges the dilute solution into a counterflow heat exchanger 68. Astrainer 67 prevents foreign particles from entering pipe 66. In theheat exchanger 68, the dilute solution passes through pipe 70 to thegenerator 18.

The generator 18 has a longitudinally extending wall 71 secured at oneside to the shell 12 and at the other side to condenser casing 72. Thegenerator 18 has tube sup ports 74 supporting a plurality of tubes 76which are in fluid communication with an inlet steam header 80 and anoutlet steam header 82. The steam in the tubes 76 heats the solution inthe generator 18 causing it to boil and send refrigerant vapor through afirst set of elimi- 3 nators 84 and thence througha second set ofeliminators 86 .into the condenser 20. H V g As vapor is removed fromthe solution by boiling in the generator 18, the solution in thegenerator is increased in concentration. The concentrated solution flowsfrom the generator .l8through an opening 102 into a chamber 104. Abaffie 106 in chamber 104 causes the solution to flow smoothly into apipe 108 without trapping vapor or inert gas. The pipe 108 conducts thehot concentrated solution to the heat exchanger 68 from which it flowsinto the absorber 14 through a pipe 110.. The pipe 110 enters theabsorber at a point close to the pipe 32 leading to the solutionrecirculating pump 34. Therefore, the solution recirculated by the pump84 is moreconcentrated than the solution at the other end of the shell12. It also follows that the solution withdrawn through pipe 66 forreturn to the generator 18 is more dilute than the solution at the otherend of the shell 12. There is a pressure equalizer opening 109 and adrain opening 111 between the chamber 104 and the generator .18. Thedrain opening 111 provides means for removing solution from thegenerator when it is desired to remove all the solution from themachine. The opening 111 is so small that it has a negligible etfectduring operation.

When the machine is started up after a shut down, there is a tendencyfor solution to accumulate in the generator until the difference inpressure has been established between the generator and absorber anduntil the generator and condenser are operating to remove refrigerantfrom the solution in the generator 18. As the level rises in thegenerator 18 above the normal level 112, the solution flows through pipe113 to the absorber 14. The pipe 113 has a trap 114 which maintains thepressure difierence between the generator 18 and the absorber 14.

The condenser 20 has, at spaced intervals along its length, a pluralityof transversely extending tube supports 88 which support tubes 90. A twopass condenser is shown. However, the condenser 20' may have one orthree or more passes. The tubes 90 are in fluid communication withheaders 92 and 94. A pipe 96 conducts cooling water from header 28 ofthe absorber to inlet 98 in header 94. The cooling water is dischargedfrom the condenser 20 through outlet 100. Header 92 merely providesfluid communication between the tubes of one pass and the tubes of theother pass.

Refrigerant from the condenser 20 flows through a pipe 116 to theevaporator 16. An orifice 118 in the pipe 116 controls the flow throughpipe 116 to maintain a pressure difierence between the condenser 20 andthe evaporator 16 and to prevent any substantial amount of vapor fromblowing from the condenser 20 to the evapo rator 16.

It should be understood that this refrigerating machine will have theusual controls (not shown) to start and stop the machine and control itscapacity.

While a single embodiment of the present invention has been illustratedand described, it should be understood that modifications may be made inthe construction and arrangement of elements and therefore we desire tobe limited only by the claims. I

We claim:

1. An absorption refrigerating machine comprising a unitary sealedhorizontal substantially cylindrical elongated container having thereinan absorbent and a refrigerant, an elongated partition extendinglongitudinally of said container and having each of its longitudinalsides secured to the cylindrical wall of said container to divide saidcontainer into a high pressure upper chamber and a low pressure lowerchamber, a generator and a condenser in the high pressure upper chamberof said container, an absorber and an evaporator in the low pressurelower chamber of said container, said evaporator being constructed andarranged with respect to said elongated partition to provide adownwardly extending passageway between the evaporator and saidelongated partition for the flow of refrigerant vapor from saidevaporato said container for conductingabsorbent frofiisaid generator tosaid absorber, conduit means extending exterior to said container forconducting absorbent from said absorber to said generator, means forconducting refrigerant from said condenser to said evaporator and meansin said high pressure upper chamber for conducting refrigerant from saidgenerator to said condenser.

2. An absorption refrigerating machine comprising a unitary sealedhorizontal substantially cylindrical elongated container having thereinan absorbent and a nefrigerant, an elongated partition extendinglongitudinally of said container and having each of its longitudinalsides secured to the cylindrical wall of said container to form with thesubstantially cylindrical wall of said container a high pressure upperchamber and a low pressure lower chamber, a generator and a condenser inthe high pressure upper chamber of said container, an absorber and anevaporator in the low pressure lower chamber of said container, saidabsorber being in the lowermost portion of the container, saidevaporator being arranged above said absorber and being spacedhorizontally from said partition to provide a downwardly extendingpassageway between said evaporator and said partition for the flow ofrefrigerant vapor from said evaporator to said absorber.

3. An absorption refrigerating machine comprising a unitary sealedhorizontal substantially cylindrical elongated container having thereinan absorbent and a refrigerant, an elongated partition extendinglongitudinally of said container and having each of its longitudinalsides secured to the cylindrical wall of said container to form with thewall of said container a high pressure chamber anda low pressurechamber, both of the chambers extending substantially the length of saidcontainer, a generator and a condenser in the high pressure chamber ofsaid container, an absorber and an evaporator in the low pressurechamber of said container, said absorber being in the lowermost portionof said container, said evaporator being above said absorber and beingoffset from the vertical diametrical plane of said container, saidgenerator being above said absorber and being offset from the verticaldiametrical plane of said container in a direction opposite to theoffset of said evaporator, means in said high pressure chamber forconducting refrigerant vapor from said generator to said condenser, andmeans in. said low pressure chamber for conducting refrigerant vaporfrom said evaporator to said absorber.

4. An absorption refrigerating machine comprising a unitary sealedhorizontal substantially cylindrical elongated container, means dividingsaid container longitudinally into a high pressure chamber and alowpressure chamber with the high pressure chamber above said low pressurechamber, a generator and a condenser in said high pressurechamber, anabsorber and an evaporator in said low pressure chamber, means forconducting refri'gerant vapor from said generator to said condenser,means for conducting refrigerant vapor from said evaporator to saidabsorber, a first conduit for conducting absorbent solution from saidgenerator to said absorber, and an overflow conduit separate from saidfirst conduit throughout its length and having one end in fluidcommunication with said generator at a point above the normal operatinglevel of solution in said generator and having its other end in fluidcommunication with said absorber to provide a second passageway for flowof absorbent solution from the generator to the absorber when the levelof absorbent solution in the generator rises above the normal operatinglevel.

5. An absorption refrigerating machine comprising an absorber, anevaporator, a generator, and a condenser in a sealed system containingan absorbent and a refrigerant, means for conducting refrigerant fromsaid generator to said condenser, means for conducting refrigerant fromsaid condenser to said evaporator, means for conducting refrigerant fromsaid evaporator to said absorber, a first conduit for conductingabsorbent from said absorber to said generator, a pump in said firstconduit, a second conduit in fluid communication with the generatorbelow the normal operating level of absorbent in said generator forconducting absorbent from said generator to said absorber, means fortransferring heat between said first and second conduits, and a thirdconduit having one end in fluid communication with said generator at apoint above the normal operating level of solution in the generator,said third conduit bypassing said heat exchanger and being in fluidcommunication with said absorber to conduct fluid from said generator tosaid absorber when the level of absorbent in the generator rises abovethe normal operating level.

6. An absorption refrigerating machine comprising an absorber, anevaporator, a generator, and a condenser in a sealed system containingan absorbent and a refrigerant, means for conducting refrigerant fromsaid generator to said condenser, means for conducting refrigerant fromsaid evaporator to said absorber, a first conduit for conductingabsorbent from said absorber to said generator, a pump in said firstconduit, a second conduit in fluid communication with the generatorbelow the normal operating level of absorbent in said generator forconducting absorbent from said generator to said absorber, a heatexchanger interposed in said first and second conduits to transfer heattherebetween, and a third conduit in fluid communication with saidgenerator and said absorber, said third conduit bypassing said heatexchanger, a liquid trap in said third conduit to prevent flow of vaporfrom said generator to said absorber, said third conduit beingconstructed and arranged to conduct absorbent irom said generator tosaid absorber only when the level 6 of absorbent in the generatorsubstantially exceeds the normal operating level.

7. An absorption refrigerating machine comprising a unitary sealedhorizontal substantially cylindrical elongated container having thereinan absorbent and a refrigerant, an elongated partition extendinglongitudinally of said container and having each of its longitudinalsides secured to the cylindrical wall of said container to divide saidcontainer into a high pressure upper chamber and a low pressure lowerchamber, a generator and a condenser in the high pressure upper chamberof said container, said generator and'said condenser being constructedand arranged in said high pressure upper chamber so that no substantialportion of said condenser is in vertical alignment with said generator,an absorber and an evaporator in the low pressure lower chamber of saidcontainer, said evaporator being constructed and arranged above saidabsorber, first conduit means extending exterior to said container forconducting absorbent from said generator to said absorber, secondconduit means extending exterior to said container for conductingabsorbent from said absorber to said generator, means for conductingrefrigerant from said generator to said condenser, and means forconlucting refrigerant from said evaporator to said absor er.

References Cited in the file of this patent UNITED STATES PATENTS2,196,911 Getaz Apr. 9, 1940 2,365,797 Bichowsky Dec. 26, 1944 2,378,177Bichowsky June 12, 1945 2,678,547 Ashley May 18, 1954 2,755,635 BourneJuly 24, 1956 2,770,953 Leonard Nov, 20, 1956

